Occupancy strongly influences faecal microbial composition of wild lemurs.

The microbiota of the mammalian gut is a complex ecosystem, the composition of which is greatly influenced by host genetics and environmental factors. In this study, we aim to investigate the influence of occupancy (a geographical area of habitation), species, age and sex on intestinal microbiota composition of the three lemur species: Eulemur fulvus, E. rubriventer and E. rufifrons. Faecal samples were collected from a total of 138 wild lemurs across Madagascar, and microbial composition was determined using next-generation sequencing of PCR-amplified 16S rRNA gene fragments. Consistent with reports from other primate species, the predominant phyla were Firmicutes (43 ± 6.4% [s.d.]) and Bacteroidetes (30.3 ± 5.3%). The microbial composition was strongly associated with occupancy in the E. fulvus population, with up to 19.9% of the total variation in microbial composition being explained by this factor. In turn, geographical differences observed in faecal microbiota of sympatric lemur species were less pronounced, as was the impact of the factors sex and age. Our findings showed that among the studied factors occupancy had the strongest influence on intestinal microbiota of congeneric lemur species. This suggests adaptation of microbiota to differences in forest composition, climate variations and correspondingly available diet in different geographical locations of Madagascar.